Conversion of (CH.sub.3).sub.3 Al and NH.sub.3 to aluminum nitride is known: Bahr, FIAT, Rev. Ger. Sci., Inorg. Chem. II, 155 to 179 (1948). The reaction is as follows: EQU (CH.sub.3).sub.3 Al.NH.sub.3 .fwdarw.(CH.sub.3).sub.2 AlNH.sub.2 .fwdarw.CH.sub.3 AlNH .fwdarw.AlN.
There is no teaching or suggestion that the CH.sub.3 AlNH intermediate was isolated or that the final reaction step was conducted in the presence of ammonia.
Laubengayer et al., J. Amer. Chem. Soc., 83, pages 542 to 546 (1961), disclose the reactions of amines at low temperatures with aluminum alkyls or alkyl aluminum chlorides to form 1:1 addition compounds. When such addition compounds having N--H and Al--R bonding are pyrolyzed, intermolecular condensation occurs, alkanes are evolved and aluminum-nitrogen polymeric products are formed. By control of the conditions of pyrolysis, the condensation results in a sequence of reactions producing amide aluminum polymers, imide aluminum polymers and, finally, aluminum nitride.
Laubengayer et al., Inorg. Chem., 1, pages 632 to 637 (1962), disclose the reaction of triphenylaluminum and methylamine in toluene solution to form methylamido triphenylaluminum. This adduct loses benzene when heated in a vacuum and forms methylamine diphenylaluminum which in turn evolves benzene to form methyliminophenylaluminum. Triphenyl aluminum and dimethylamine react in toluene solution to form dimethylamine triphenylaluminum which is heated to form dimethylamido diphenylaluminum.
Cohen et al., J. Chem. Soc., pages 1092 to 1096 (1962), disclose that ethylaluminum dichloride and diethylaluminum chloride form complexes with ammonia. There is no ammonolysis of aluminumchlorine bonds. On heating, the complexes lose ethane and aluminum trichloride-ammonia, with the formation of aluminum-nitrogen polymers. They also disclose the reaction of (C.sub.2 H.sub.5).sub.3 Al and NH.sub.3, and conversion of the product to C.sub.2 H.sub.5 AlNH which is described as polymeric and insoluble in organic solvents. Said polymer, however, is substantially infusible and therefore could not be converted to desirable morphologies by melt-forming techniques.
Interrante, in a meeting of the Materials Research Society, April, 1986, at Palo Alto, CA, disclosed the conversion of C.sub.2 H.sub.5 AlNH to aluminum nitride in the presence of ammonia. The aluminum nitride produced with ammonia contained less carbon than that formed without it. Interrante also disclosed that C.sub.2 H.sub.5 AlNH is converted to aluminum nitride at 300.degree. C. to 900.degree. C. with retention of morphology.